Time in Wireless Embedded Systems

Thomas Schmid
Advisor: Mani B. Srivastava

Tuesday, September 15, 2009 at 4:00pm-6:00pm
Engr IV Room 67-124

Abstract:
Wireless embedded networks have matured beyond academic research as industry now considers the advantages of using wireless sensors. With this growth, reliability and real-time demands increase, thus timing becomes more and more relevant. In this dissertation, we focus on the development of highly stable, low-power clock systems for wireless embedded systems.

Wireless embedded networks, due to their wire-free nature, present one of the most extreme power budget design challenges in the field of electronics. Improvements in timing can reduce the energy re-quired to operate an embedded network. However, the more accurate a time source is, the more power it consumes. To comprehensively address the time and power problems in wireless embedded systems, this dissertation studies the exploitation of dual-crystal clock architectures to combat effects of temperature induced frequency error and high power consumption of high-frequency clocks. Com-bining these architectures with the inherent communication capabilities of wireless embedded sys-tems, this dissertation proposes two new technologies; (1) a new time synchronization service that automatically calibrates a local clock to changes in temperature; (2) a high-low frequency timer that allows a duty-cycled embedded system to achieve ultra low-power sleep, while keeping fine granular-ity time resolution offered only by high power, high frequency clocks.

Biography:
Thomas Schmid graduated in 2005 from the Ecole Polytechnique Federale de Lausanne, Switzerland with a M.Sc. in Communication System Engineering. In the same year he joined the Networked & Em-bedded Systems Laboratory (NESL) at UCLA to pursue his PhD studies in Embedded Computing Systems. His research interests include software radios, large scale sensing systems, and sensing systems for natural resource consumption management.